The present invention relates to a cable raceway used to transmit cable along a structure to an electrical or wiring device and more particularly to a base plate and cover for supporting an electrical device or wiring device at an opening in the cover of the raceway.
Cable raceways support and enclose electrical cables to bring them to wiring devices or electric devices requiring the cables. A raceway may be attached to or inside and extends along a wall or ceiling. A simple form of raceway design includes a U-shaped hollow body, open on one side, and the open side is covered by a securable, removable cover to enclose the hollow raceway. The bottom wall of the raceway is generally the wall attached to the structure along which the raceway extends, so that the cover of the raceway faces outward to the side of the raceway.
A typical wiring device at the cable raceway might be any device which is to be connected to some cables passing through the raceway. The wiring device is typically supported at the raceway cover and may be supported on the cover or on a plate on the cover, etc. There is no limit on the size, configuration, or number of cable connection to a wiring device, except of course that the wiring device has to be supportable on the particular raceway embodiment. The wiring device itself typically includes support elements, e.g. brackets tabs, flanges, etc., by which it is intended that the wiring device be supported on a surface, such as on the raceway or in a wall.
At each interval along the raceway where a wiring device or electrical use device is to be positioned, there is an opening in the cover of the raceway at which the wiring device is positioned. Some of the cables in the raceway are attached to the wiring device.
A portion of the wiring device projects behind the cover or the surface of the raceway on which it is supported and projects into the raceway. It may project quite far to the bottom or rear of a shallow raceway leaving insufficient space behind the wiring device for the cables and the connection of the cables to the particular wiring device. It is often useful to be able to raise a wiring device further forward out of the raceway than positioning it on the cover over a shallow raceway would otherwise permit.
A raceway may carry cables for several purposes and at several voltages, e.g. cables supplying electricity to machinery or for operating lights and appliances, and also cables for supplying low voltage or low power equipment, such as telephones or telecommunications equipment. To prevent interference in either of the different types of cables carried in the raceway, especially due to different voltages, and to satisfy building codes of different localities, the different types of cable, e.g. cables carrying quite different voltages, should be segregated from each other in their paths along the raceway. To this end, it is typical to provide a dividing strip extending along the length of the raceway, located generally midway across the width dimension between the side walls of the U and projecting out from the bottom or rear wall of the raceway and extending to the open end or the front of the raceway, with the outer edge of the dividing strip being at the level of the edges of the side walls of the raceway. The cover closing the raceway rests on the edges of the raceway side walls and closes against the top of the dividing strip.
One or more wiring devices can be positioned at one open area along the raceway cover. Each wiring device or several wiring devices may include connections for cables carrying different voltages. For example, at a wall socket or receptacle, one frequently sees an electric socket with two higher voltage outlets for receiving electric plugs for lights or domestic appliances and two plug sockets for telephone or for other low voltage supply jacks or plugs. Alternatively, there may be a first wiring device along the raceway with only higher voltage electrical sockets and a second wiring device elsewhere along the raceway with only lower voltage sockets, e.g. telephone connections. Especially in the case of a wiring device or electrical device that has connections to two sets of cables which should normally be kept divided by the dividing wall, e.g. cables at different voltages, no means presently exists in the support on the raceway for a wiring device, and particularly in a support that raises the wiring device outward from the raceway, to keep the cables separated, for the reasons discussed above.